1. Field of the Invention
The present invention relates to a semiconductor device and an electronic component module using the semiconductor device.
2. Description of the Related Art
Conventionally, a semiconductor device is connected with a circuit board or the like by means of soldering. For example, a BGA package is generally utilized for a semiconductor device with high speed operationality and a large number of pins. The BGA package is configured such that a semiconductor device is mounted on one main surface of a circuit board and a plurality of solder balls functioning as external connectors are provided on the other main surface of the circuit board. The BGA package is soldered on another circuit board called as a mother board by melting the solder balls.
When the semiconductor device is connected through soldering, it is required that the solder is heated to a temperature higher than the melting point and thus, melted so that the semiconductor can be separated from the circuit board. In this point of view, it is difficult to repair the semiconductor device after the soldering. Moreover, the semiconductor is heated to a temperature higher than the melting point of the solder so as to be connected with the circuit board in advance. Therefore, since the semiconductor device is heated again at the higher temperature than the melting point of the solder at the separation, the repair of the semiconductor device may be inhibited if the thermal resistance of the semiconductor device is lower.
On the other hand, in order to realize the downsizing and/or the high density integration of the semiconductor device, such a multi-chip module (MCM) as accommodating and systematizing a plurality of semiconductor elements in one package is practically employed. As a typical MCM, such a packaging structure as mounting one or more memory elements and processor elements on one circuit board and sealing the thus obtained assembly as a whole may be exemplified. In view of the high density package of the MCM satisfying the requirement of the downsizing thereof and the development in function thereof, moreover, the commercial application of a packaging structure, POP (Package on Package) is being proceeded where a plurality of circuit boards with the corresponding mounted semiconductors are stacked three-dimensionally.
As a concrete structure of the POP, such a multistage structure as stacking a plurality of BGA packages is well known (refer to Patent Document No. 1). With the conventional POP, since the adjacent packages are connected with one another by means of soldering, it is required in the separation of the adjacent packages that the POP assembly is heated to a temperature higher than the melting point of the solder. In this point of view, it is difficult to repair the conventional POP and the repair of the conventional POP may be inhibited if the thermal resistance of the POP is lower.
[Patent Document No. 1] JP-A 2004-241713 (KOKAI)